Peculiarities with Time Capsule and SB6141

Discussion in 'Mac Accessories' started by skyhighmcfly, Apr 16, 2015.

  1. skyhighmcfly macrumors newbie

    Apr 16, 2015
    Here's my set up:
    Cable internet over Coax to a Motorola SB6141 DOSCIS 3.0 Modem
    Connected to a TimeCapsule (2011, previous generation) for WiFi
    Additionally, I have an airport express (current generation) wired to one of the Time Capsule's ethernet ports, acting as an additional Wireless Access Point in my basement (to extend our wifi range)

    I have been having three issues:
    1. My internet connection slows down and then drops out. All of my devices still show a wifi signal, and I am still able to access the config page of the modem, but no web pages. If I reset the modem everything is fine. I thought the modem was going bad, and bought a new one yesterday (same model) and am still having the issue.

    2. My time capsule will seemingly drop off crap out (green light starts flashing orange) but since the airport express has the same SSID, all devices connect to it. Since the time capsule is crapped out, there is no internet signal at the airport express, and I end up having to reset all devices.

    3. Some times after resetting devices for issues 1 and 2 above, the ethernet connection between the time capsule and the airport express will go out. My home is wired with ethernet, and the only way to re-establish the connection is to connect my laptop to each of the ethernet connection points to 'draw' the signal down to the airport express. (connect laptop to the time capsule and ensure connectivity, then connect to the patch panel and ensure connectivity, then connect to the wall jack by the airport express...etc.)

    Any correlation or suggested solutions? I am trying to avoid buying a new Time Capsule...


  2. eduardrw macrumors 6502

    May 20, 2013
    I have Comcast using the same cable modem and an apple Time capsule 2011 directly connected to the modem.

    The combination works stable and fine.

    Here is what I suggest for troubleshooting:

    1. Turn power off for your 6141 modem wait 30 sec then turn it on
    2. do a full reset for your time capsule. Then configure the Time Capsule via AirportUtility as a router with all of your settings.

    If that does not work you may need to troubleshoot your cable connection with your provider.

    If the Cable modem gets no service either from the coax able being unplugged or the cable network has the modem in a disabled state or it simply cant sync for some reason it will turn its DHCP server and provide a DHCP to anything hooked to the Ethernet port whether its a router or computer or anything giving that device an IP in the range whether its a computer or routers WAN port or anything.

    If you can see this type of address as the WAN address of your Apple router you know that the problem is with the coax side.

    You can also connect to the status page of the 6141 modem to look for problems recorded there - the ip address is
  3. Altemose macrumors G3


    Mar 26, 2013
    Elkton, Maryland
    1. It has been reported that the AirPorts and the SB6141 have an incompatibility. Some other routers are also affected with this. That being said, the SB6121 and SB6183 work just fine from personal experience and what I have heard. The SB6141 incompatibility only appears in some circumstances.

    2. Is the Time Capsule still visible in AirPort Utility when it dies out?

    3. It sounds like there maybe a DHCP issue going on here and unplugging and replugging Ethernet cables or testing them on your laptop is resetting it. This maybe due to a couple of different reasons, but we must resolve #2 first.
  4. eduardrw macrumors 6502

    May 20, 2013
    If one follows the "start-up" sequence I described in my post above it works just fine.(turn 6141 modem off by pulling power plug. Pull plug from Time capsule. Start modem and wait until all the status lights are blue. Then start Time capsule)

    The SB6141 supports IPv6 and if you follow above sequence, it will acquire all the right addresses.

    The reported "problems" seem to stem from not going through this sequence once properly.
  5. Altemose macrumors G3


    Mar 26, 2013
    Elkton, Maryland
    I have noticed that as well, but never had enough testing to back my theory. That being said, with people asking for a modem recommendation I generally send them to the SB6183 now, which does not require that game to get it to work with AirPorts.

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